Cable releasing clamp



Oct. 17, 1933. J JESTER 1,930,878

CABLE RELEASING CLAMP Filed Sept. 20, 1928 2 Sheets-Sheet 1 FIG. 2 gwoentoz John M'Zfozz Jesfer @255 3?, E933. J. M. JESTER 3 9 CABLE RELEASING CLAMP Filed Sept. 20, 1928 2 Sheets-Sheet- 2 Jolm Miltan lfesfer Patented Oct. 17, 1933 PUZNETED STATES Parent @FFHCE Application September 20, 1928 Serial No. 307,137

12 Claims. (Cl. 248-31) The invention relates to clamps for the suspension of the conductors of high power lines.

It is well known in the art that high power lines are suspended from supporting towers through the medium of a string of insulators, the conductor being held by a clamp at the lower end of the string. The span between successive towers is frequently quite long and it occurs that strains at opposite sides of any tower are widely difl0 ferent. For example it often occurs that an accumulation of sleet forms upon the conductor at one side of the tower whereas the conductor at the other side may be clear. The weight of any such accumulation has a tendency to pull the tower over. It is not feasible to make the towers so strong as to be capable of withstanding every conceivable strain and it therefore becomes necessary to take care of the specified conditions in a different manner.

It is with the above facts in view that I have devised the present invention which has for its general object the provision of a suspension clamp which will grip the conductor firmly under ordinary circumstances but which will release and 5 permit the conductor to slip through in the event of an unusual strain at one side or the other of a supporting tower, it being therefore possible for the cable to adopt such a position or condition as to equalize the strains.

0 Another object of the invention is to provide a conductor clamp which does not rely upon springs alone for its clamping action and which will therefore be positive in its grip.

Another object is to provide a clamp so constructed as to permit a certain limited longitudinal movement of the conductor without releasing its grip thereon, the releasing means becoming operative only when the strain becomes excessive.

Still another object of the invention is to provide a conductor supporting clamp of the character mentioned which will re-grip the conductor upon the cessation of the force which initially operates to release it so that a manual resetting or readjustment of the parts will be unnecessary.

Still another object of the invention is to provide a'clamp of this type which will operate with efficiency regardless of minor variations in the size of the conductor and equally well whether the conductor be armored or not.

A further object of the invention is to provide a clamp of this character which will be simple and inexpensive to manufacture, easy to install, positive in action, efiicient and durable in service, and a general improvement in the art.

To the attainment of the foregoing and other objects and advantages, the invention preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, and 6,0 I illustrated in the accompanying drawings in which:

Figure 1 is a side elevation of the complete device, 1

Figure 2 is a longitudinal sectional view therethrough,

Figure 3 is an end View,

Figure 4 is a horizontal cross section taken on substantially the line 1-4 of Figure 1,

Figure 5 is a detail section on the line 5-5 of Figure 1, and

Figure 6 is a similar view taken on the line 66 of Figure 1.

Referring more particularly to the drawings, I have shown the device as comprising, generally speaking, upper and lower clamping members 1 and 2 and suspension means 3. The clamping members are adapted to be engaged upon opposite sides of a conductor a and it is preferable that their ends flare outwardly as indicated to avoid bringing any abrupt bending strains upon the conductor. The lower clamping member 2 is longitudinally grooved at 5 or otherwise formed to provide an adequate seat or bearing surface contacting with the conductor and the clamping member 1 is of more or less hollow formation so as to contain the automatic conductor gripping means to be described. The members 1 and 2 are intended to be held in assembled relation to the conductor as by means of studs or the like 6 here &2 shown as passing through laterally extending ears 7 and 8 on the members 1 and 2 respectively.

The suspension means 3 is here represented as comprising a pair of links 9 which may be formed for connection with whatever element is provided at the lower end of a string of suspension insulators, not shown, the drawings, however, illustrating a pin 10 which would be used if said element should happen to be of the clevis type. At their lower ends these links are preferably widened as indicated at 11 and are formed with holes 12 pivotally engaged upon trunnions 13 which project laterally from the upper clamping member 1. It is of course readily conceivable that any mechanical equivalent of these trunnions may be provided and that it is immaterial whether they are formed upon the upper clamping member or the lower one, the point being that the assembled clamping members must be capable of pivotal movement with respectto.the'suspension H0 means. The widened lower ends of the links are also formed with cam slots 14 for a purpose to be described.

As mentioned above, the upper clamping memher 1 is of hollow formation or chambered or recessed as indicated at 15 so as to house a pair of wedge members 16 which are preferably grooved at 17 to engage conformingly against the conductor. These Wedge members have inclined upper surfaces 18 coacting with the upper portion or the clamping member 1 and are urged outwardly or away from each other as by a spring 19 interposed between their inner ends and preferably seated within sockets 20. Clearly, the coaction of the inclined upper faces of the wedges with the upper clamping member will cause them to have a tendency to move toward the conductor and grip the same.

The releasing means is here disclosed as comprising pins or stubs 21 projecting laterally from the wedges 16 and extending through openings 22 in the sides of the upper clamping member 1 and located within the cam slot 14 and so positioned with respect to the outer walls thereof as to be engaged thereby when the assembled clamping members move beyond a certain predetermined extent with respect to the suspension links.

To effect mounting or installation of the device, the links 9 should be engaged upon the trunnions 13 and swung with respect to the upper clamping member 1 to bring the outer edges of the cam slots 14 into engagement with the pins or stubs 21 and thereby retract the wedges 16 or move them toward each other against the resistance of the spring 19. Both clamping members may then be applied to the conductor 4, subsequently to which the studs 6 are inserted and screwed home for permanently connecting the clamping members. After this is done the links 9 are returned to normal position at right angles to the conductor whereupon the retracting pressure upon the wedges is released, permitting the wedges to move outwardly or away from each other under the influence of the spring 19. The coaction of the inclined top surfaces of the wedges with the upper clamping member will force them into close engagement with the conductor and it is obvious that any tendency of the conductor to move longitudinally with respect to the clamping members will increase the wedging pressure, resulting in a firm and fast holding action.

The formation of the cam slots 14 is such that the suspension links may have a certain limited pivotal movement withrespect to the assembled clamping members without engaging and mov ing the pins or stubs 21 and consequently the wedges, but just as soon as the links move through a certain arc with respect to the clamping members, a movement such as would occur for example if an accumulation of sleet or ice were to form upon the conductor at one side or the other of a tower, the edges of the cam slots will engage the stubs or pins and retract the wedges, thus destroying, temporarily, their gripping power and permitting the conductor to slip through. As soon as the conductor has thus slipped to balance the strains at both sides of the tower where the clamp is located, the return of the device to its normal or upright position will permit the wedges to resume their gripping position. Manual resetting ofthe clamp is consequently unnecessary at any time.

From theforegoing description and. a study of the drawings it will beapparent that I have thus provided a simply constructed and easily installed clamp capable of releasing itself automatically under the conditions specified. Furthermore the construction is clearly such that there will be an automatic accommodation or adjustment to take care of any variations which may occur in the size of the conductor, this faculty being probably sufficient to take care of the presence or absence of any armor which may be provided about the conductor. It should be noted that the device is similarly capable of automatically taking up or compensating for any wear and it is equally apparent that under nor- .mal circumstances there is no engagement of the cam slots with the releasing pins and consequently no friction thereon such as would otherwise cause a wearin away. It is thought that the construction, operation and advantages should be readily apparent to one skilled in the art without further explanation.

While I have shown and described the preferred embodiment of the invention, it should be understood that the disclosure is merely an exemplification of the principles involved as the right is reserved to make all such changes in the details of construction as will widen the field of utility and increase the adaptability of the de vice provided such changes constitute no departure from the spirit of the invention or the scope of the claims hereunto appended.

Having thus described the invention, I claim:

1. In a device of the character described, a pair of clamping members adapted for disposition upon a conductor, suspension means for the clamping members, gripping means located within the assembled clamping members, and means coac'ting with said suspension means for rendering said gripping means ineffective.

2. In a device of the character described, a pair of members adapted for engagement upon a conductor, suspension means for said members and conductor gripping means operatively connected with the suspension means and rectilinearly slidably releasable thereby upon predetermined movement thereof with respect to the members.

3. In a device of the character described, a pair of members disposed upon opposite sides of a conductor, suspension means for said members, wedge means mounted within the assembled members and normally engaging the conductor, and means coacting with said wedge means and the suspension means for rendering the former ineifective when the latter moves beyond a predetermined extent with respect to the members.

4. In a device of the character described, a pair of members engageable upon a conductor, suspension means for said members, conductor gripping wedges within the assembled members, and cam means for controlling the position of the wedges.

5. In a device of the character described, a pair-of members engageable upon a conductor, suspension means for said members, conductor gripping wedges within the assembled members, and means coacting with the wedges and the suspension means for rendering the former ineiIective upon predetermined movement of the latter with respect to the members.

6. A device of the character described com- Jill prising members engageable upon a conductor, 1

sion means for rendering the former ineffective 1 upon movement of the latter with respect to the members beyond a predetermined limit.

7. A device of the character described comprising members engageableupon a conductor, conductor gripping wedges housed within the members, suspension means connected with the members, and means cooperating with the wedges and the suspension means comprising cams on the suspension means and elements carried by the wedges and cooperating therewith.

8. A device of the character described comprising members disposable against a conductor, means for holding said members together, Wedges housed within said members and coasting with the conductor, suspension links pivotally connected with the assembled members, and cam means on the suspension links cooperating with the Wedges for retracting the same into ineffective position when the links move beyond a predetermined extent with respect to the members.

9. A device of the character described comprising members disposable against a conductor, means for holding said members together, wedges housed within said members and coasting with the conductor, suspension links pivotaliy connected with the assembled members, and cam means on the suspension links cooperating with the wedges for retracting the same into inefiective position when the links move beyond a predetermined extent with respect to the members, the cam means including slots in the links and elements carried by the wedges, projecting through openings in one member and accommodated within said slots.

10. In a suspension clamp mechanism, the combination of clamping members engageable upon a conductor means cooperating with said clamping members for releasably maintaining the same in clamping position upon the conductor, a suspension device for supporting said clamping members, and means on said suspension device cooperating with said first named means for rectilinearly sliding the latter bodily to conductor releasing position upon movement of the suspension device with respect to the clamping members beyond a predetermined extent.

11. In a suspension clamp mechanism, the combination of clamping members engageable upon a conductor, slidable means cooperating with said clamping members for normally maintaining a clamping action upon the conductor,

a suspension device for supporting said clamping members, and coacting means on the suspension device and longitudinally rectilinearly slidable means operable upon movement of the suspension device beyond a predetermined position with respect to the clamping members for moving said slidable means into a position rendering said clamping members inefiective.

12. In a suspension clamp mechanism, the combination of clamping members engageable upon a conductor, means bodily rectilinearly slidable longitudinally of said clamping members and cooperating therewith 1or normally maintaining a clamping action upon the conductor, a suspension device for supporting the clamping members and movable with respect thereto, and coacting means on said suspension device and longitudinally slidable means operable upon movement of the suspension device beyond a predetermined position with respect to the clamping members for moving said longitudinally slidable means into a position rendering said clamping members inefiective.

JOHN MILTON JESTER. 

